Adjustable load engaging means for lift truck



Ovvio'.

E. P. REPKE 3,075,665

ADJUSTABLE LOAD ENGAGING MEANS FOR LIFT TRUCK Filed DSG. 5, 1960 INVENTQR EDWARD P. REPKE ATTORNEY United States Patent Office 3,@7565 Patented dan. 29, 1963 3,075,665 ADBUSTABLE LGAD ENGAGENG lt/EANS FR LEFT TRUCK Edward P. Repite, (Idioma, Mich., assigner to Clark Equipment Company, a corporation of Michigan Fiied Bec. 5, 196i?, Ser. No. 73,713 7 Claims. (Qi. 214-731) rlhis invention relates to a mounting construction for a lift truck load engaging means and more particularly to a mounting construction which provides full lateral adjustment for pivoted load engaging means.

In the use of certain lift trucks having a pair of fork tines mounted forwardly thereof for engaging, lifting and transporting material, it is desirable that the fork tines be fully adjustable transversely of the truck, as well as being pivotable about a transverse horizontal axis. it is known to mount such fork tines for pivotable movement as aforesaid and to provide limited lateral adjustment therefor, but to my knowledge no prior mounting construction of the type contemplated provides for full lateral adjustment of pivoted fork tines.

it is therefore an important object of the present invention to provide an improved mounting construction for load engaging means of the type contemplated which permits both full lateral adjustment and pivotable movement of the load engaging means.

Another object of the invention is to provide an irnproved fork tine mounting construction associated with the lifting carriage of a lift truck in which separate means are provided for the support of and for the pivot suspension of the fork tines.

Another object of the invention is to provide a generally improved mounting construction for fork tines or other load engaging means of lift trucks.

In carrying out my invention I provi-de a lifting carriage which is associated with a mast construction of a lift truck in known manner and which provides a transverse load supporting beam, a transverse pivot shaft adjacent the beam, transversely movable load supporting bracket means connecting the beam and pivot shaft, and a pair of fork tines suspended from the pivot shaft and movable transversely with the bracket means from a position adjacent one side of the carriage to a position adjacent the opposite side thereof.

In the drawings:

FGURE 1 is a partial view in perspective of the forward end of a lift truck having the mounting construction of the present invention associated with the lifting carriage thereof; and

FIGURE. 2 is a side view in partial section of the lifting mast and fork mounting construction shown in PEG- URE l.

Referring now in detail to the drawings, the lower portion of a telescoping lifting mast construction of a lift truck is illustrated at numeral and is pivotally supported from and forwardly of a drive axle, not shown, and intermediate a pair of drive wheels 12 which are mounted at opposite ends of the drive axle. A pair of laterally spaced tilt cylinders 14 are connected to the truck and to the lifting mast for pivoting the mast about the drive axle. A portion of the body construction of the lift truck is shown at numeral 16.

The mast construction may be like that which is de scribed in detail in copending continuation application Serial No. 111,076, tiled May 18, 1961, in the names of Hastings and Backofen (common assignee). As illustrated herein it comprises a pair of transversely spaced inwardly opening fixed channel members i8 supported, as aforesaid, upon the drive axle of the truck, a pair of partially nested transversely spaced and elevatable l-beam sections Z0 mounted for telescoping vertical movement relative to the fixed beams 1S and offset forwardly thereof so that the forward flanges of the I-beams overlap the forward iianges of channel beams 13, and an upright hydraulically actuated cylinder motor hoist 22 intermediate of I-beams 2t). Hoist motor 22 is pivotally mounted at its lower end upon a transverse pin 24 which is supported in a pair of transversely spaced plates 26, one of which is shown in FiGURE 2. Plates 26 are supported upon a horizontal plate member 23 which connects the lower ends of the beams 1S. In the interest of clarity, only the base end of hoist motor 22 is illustrated in FIG- URE 2, and guide roller members which are connected between beam members 2d' and 18 for supporting the telescoping l-beams in channel members 18 are not shown in FiGURE 2.

Mounted forwardly and extending transversely of the mast construction lil is a carriage and fork mounting assembly 3d which is supported from the I-beams 20 for vertical movement along mast it), being connected to hoist motor 22 in conventional manner by means of a pair of lifting chains 32 which are secured to the carriage construction at the one ends thereof by a pair of bracket members 34 and to a fixed portion of the mast at the other ends thereof. Chains 32 extend over rotatable sprockets, not shown, which are connected to the upper end of the piston rod of hoist motor 22.

The carriage assembly comprises a pair of laterally spaced and vertically extending end frame members 36 interconnected by a pair of vertically spaced and transversely extending beams 38 and 40 and a pivot shaft 42 spaced slightly forwardly of and beneath beam 40. Shaft 4Z is preferably mounted at its opposite ends in resilient support rings d3 located in end members 36. Intermediate end members 36 is located a pair of transversely spaced and rearwardly extending carriage support plates dd which are securely connected to transverse beams 3S and 4t). Secured to the rearward outer portion of each support plate 44 is a pair of vertically spaced rollers 46- which are mounted for registry with the inner-facing channel portions of I-beams Ztl for supporting the carriage assembly in the mast assembly 10 for vertical guided movement with respect thereto. Support plates 44 are connected intermediate the upper and lower ends thereof by a pair of vertically spaced and transversely extending plate members 48, which are in turn connected together by a vertically extending beam located centrally between plates 44 and secured at the lower end to beam 38. An additional transversely extending plate member 52 connects support plates 44 adjacent the upper ends thereof. An additional pair of mounting plate members 54 are secured along inner edges thereof to the forward outer surface portion of support plates 44, and extend transversely outwardly thereof for receiving vertically spaced pairs of side thrust rollers 56 which are mounted for rolling engagement with the overlapping outer edge portions of the forward flanges of I-beams 20.

From pivot shaft 42 depends a pair of transversely spaced fork tines 6d, each of which includes an upper bifurcated journal portion 62 for engaging the pivot shaft as shown. The upper forwardly extending end of each support plate 44 terminates in a downwardly diagonally extending surface 64, and main transverse support beam member 4t), which is shown of rectangular cross-section, is secured rigidly to each surface 64, as by welding, on the lower long side of the section. Beam 4t) is also secured at its opposite ends to carriage frame members 36.

A pair of generally U-shaped brackets 66 including a hook portion 69 embrace the four surfaces of beam 4t), as shown, and register with pivot shaft 42 intermediate the bifurcated upper end portions 62 of each fork tine in an opening 57 formed in an enlarged boss section 68 of each bracket. The lower portions of the vertical legs of the fork tines normally rest against the forward surface of beam 38, which resists the rearward thrust of a load on the fork tines tending to rotate same in a clockwise direction as viewed in FIGURE 2. Assembly notches 70 arecut out. of the rear Surface portion of beam Mlwfand are of slightlygreater width thantthey width of brackets 66. In assemblingthe carriageconstruction with` thek beam 40' secure-dto support lplates A44, brackets 66 are threaded on the beam from opposite ends thereof a distance sutcient to permit forkends ,62,tobe aligned with openings67 for receiving shaft 42.V Then,y with shaft 42 in vposition in resilient supports43 of end bars 36, brackets 66 cannot be,moved,transversely outwardly a suflicient distance to drop into assembly notches 70 and become unintentional- -ly unhooked from ,beam 40 without removal of shaft 42. Resilient supports 43are preferably of sufficient rmness to ,support in position elements 42, 60 anddwhen. no load isv supported by the fork tines, thus allowing a free itting` relation between elements 66 and 40 which permits stvanda'rdmill rolled tolerances to be specified for the dimensions ,of beam 40Which otherwise would require a machined finish As load is applied to the fork tines 6G' the resilientendmounts of shaft 42 yield ,suiciently to bringintofull'supporting abutment brackets fwith' beam 40.`

-As .will now befapparentlthe Weight of the forktines and anyload carried kthereby in supported from fthe transverse beam 40,1and'not from pivot shaft 42;V Each associated 'bracket and fork -tine is adjustable manually in a direction. transverse otjthe carriage assembly-along the entirelengthpf pivot shaft 442so that any .combinationof l relative ,transverse position ofthe pair of fork `tines may` bcleifected within the space provided between vertical` frame members 36. In the present construction the pivot` shaft 142nced not be-of appreciable cross-section, as would be sufficient tosupport a relatively heavy load intermediatethe ends thereof, inasmuchas the load is supported from transverse beamv40, the pivot shaft providing meansy for permittingfpivotallmovement of the fork4 tintes in a Counterdockwise ,direction Such; 21Sv is` desirable during. rearwardnmovement of the llift truck' over uneven Vterrain.,V

In Aadditiornto vfunctioning as a forkV hinge, pivot shaft v42, is'lvan economical means for providing a machined guide whichmaintains the fork ,tinesin transverse alignment at Y all times, and theconstructionlof this invention is well suited *for use with either manual or powered lateral adjustment ofthe, fork Ytines. The present invention provides carriage and jfork tinemounting construction `in which each forktine is capable of being adjusted laterally of` the carriage substantially throughout. the transverse length,

thereof without imposing upon any portion of the carriage an excessiyeddetlection or stresslwithin the load 'carrying capacity of vthe truck.

It will be understood that reference to forkhtines her e.

in is aumattertof convenience of expression, and that any suitable pair oflloadengaging means associatable with partmgxfrom the scope of the invention as defined in the claimsrappended..

I'claim:

1; AL load supporting ,carriageV assembly for use with lift trucks comprisingla pair of `transverselyspaced verticall'y extending frameV members, a pairsof vertically4 spaced transversely extendingbeams connected to said:

frame members, a transversely extending p ivot member connectedltorsaidnframe members andlocated Aadjacent the-upper beam, alpair ofltransversely spaced load engagingmeans dependingsrfrorn said pivot member, said pivot member being supported for limited vertical movement relative toA said upper beam when said loadengaging meansis subjectedto al load,` and a pair ofY members sup` porting said pivot member from the utner one of said beams such that a load on said load engaging means causes the main support thereof to shift the support of the load from said pivot member to said upper beam, said supporting members being connected to said pivot member adjacent the connection thereto of said load engaging means and being adjustable with saidrload engaging means transversely of said pivot member-and the upper one of said beams.`

2. A load supporting. carriage. assembly for use with lift trucks having` aliftingmast construction mounted at one end yof the truck comprising a transversely extending beam, a pair of laterally spaced carriage support means secured to said beam and mounted in opposite sides ofthe lifting mast for supporting said beam forwardly of the lifting mast, a transversely extending pivot -member mounted adjacent said beam, a pair of transversely spaced load engaging means depending from said pivot member, apair of members supporting said pivot member from said beam, saidl latter supporting members being connected to said pivot member adjacent-the connection thereto of said load engaging means and being adjustable with saidl load engaging-means transversely of said pivot member and said beam, andl yielding `means' supporting said pivot :member for limited movement relative to said beam such that said supporting members-are adapted to moveinto full load supporting-abutment with said beam When-said load engaging Vmeans lis subjected to a load.

3; A'load supporting'carriage'assembly for use with lift trucks'having a vertically extending lifting mast construction mounted at one end of' the truck comprising a pair of Vvertcallyspaced transversely extending beams, a pair oftransversely spaced rearwardly extending carriage support .means connected to said beamsand suporting same in the mast construction for elevating movement, a transversely extending pivot memberspaced from the upperone-of said beams, a pair lof transversely spaced load v'engaging means Y dependingy from saidpivot member,

and a pair ofbrackets supporting said pivot memberfrom-the upper oneV of-'said beams, said brackets being connected to saidV pivot member adjacent the connection thereto offeach said load-engaging means and being adjustable with said loadengaging meansv transversely of said'pivot member and the upper one of said beams, whereby each load engaging means is pivotable outwardly of the carriage assembly and is adjustable from a position adjacentrone end of the pivot member to a position adjacent the opposite end thereof, said upper beam having notched reduced end portions of lesser width than theV Width of said brackets so that the brackets may be readily threaded on the upper beam from the ends thereof but cannot drop into said notchedend portions following assembly of the carriage.

4. A carriage assembly as claimed in claim 3 wherein` each load engaging means and associated bracket are mounted uponithe` pivot member in-interlocking relation such that the weight of the load engaging means and any load carried thereby is supported from the upper beam, and vyielding means supporting the ends of said pivot member for limited movement reiative to said upper beam whereby to assure continuous support of the load engaging means and load from said upper beam.

5. A-.load supporting carriage assembly for use with lift trucks having an upright mast construction located at one end of the truck comprising a beam member of substantially-rectangular cross-sectionsupported from and forwardly of the mast construction-for vertical movement relative thereto, said beam lmember extending transversely of the mast construction and being located in a biased plane which extends downwardly and `forwardly from the plane of the mast construction, a pair of transversely spaced generally U-shaped bracket support members. embracing said beam and movable lengthwise-thereof, each said support bracket havingA a downwardly extending portion, a transversely extending vpivot shaft in registry with 7. A carriage assembly as claimed in claim 6 wherein said beam member has notched reduced end portions of lesser width than the width of said support members.

5 References Cited in the le of this patent UNITED STATES PATENTS Ward etal May 13, 1952 Mindrum Sept. 15, 1959 

1. A LOAD SUPPORTING CARRIAGE ASSEMBLY FOR USE WITH LIFT TRUCKS COMPRISING A PAIR OF TRANSVERSELY SPACED VERTICALLY EXTENDING FRAME MEMBERS, A PAIR OF VERTICALLY SPACED TRANSVERSELY EXTENDING BEAMS CONNECTED TO SAID FRAME MEMBERS, A TRANSVERSELY EXTENDING PIVOT MEMBER CONNECTED TO SAID FRAME MEMBERS AND LOCATED ADJACENT THE UPPER BEAM, A PAIR OF TRANSVERSELY SPACED LOAD ENGAGING MEANS DEPENDING FROM SAID PIVOT MEMBER, SAID PIVOT MEMBER BEING SUPPORTED FOR LIMITED VERTICAL MOVEMENT RELATIVE TO SAID UPPER BEAM WHEN SAID LOAD ENGAGING MEANS IS SUBJECTED TO A LOAD, AND A PAIR OF MEMBERS SUPPORTING SAID PIVOT MEMBER FROM THE UPPER ONE OF SAID BEAMS SUCH THAT A LOAD ON SAID LOAD ENGAGING MEANS CAUSES THE MAIN SUPPORT THEREOF TO SHIFT THE SUPPORT OF THE LOAD 